Costing just a cent to produce and requiring just a single drop of blood to function, this paper chip, designed by chemist George Whitesides, can diagnose HIV, tuberculosis, malaria and more. What substance makes this tiny marvel possible? Comic-book ink.

The water-resistant ink pushes the blood into the different paper channels, each of which contain chemicals that react with the blood and change color to indicate the presence and severity of the various diseases.

In developing countries where technology for diagnosing diseases needs to be cheap and easy for individuals to use themselves, it's hard to imagine a test simpler than Whitesides' "zero cost diagnostics". The Harvard chemist presented his idea at a recent TED conference and summarized it in a video for CNN:

In his presentations, Whitesides explains how the paper tests could be produced cheaply in great numbers by inexpensive wax printers and proposes that individuals could send their results to doctors with cheap camera phones. Solutions for third world problems are often weighed down by their ambition and complexity, but the advantages of Whitesides' work rests in its simplicity. [CNN via PopSci via Inhabitat